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Bangston Project: Three drill targets with coincident electromagnetic conductors (coloured data) and magnetic (line contoured data) targets |
The Bangston Lake Project in Marquette County, Michigan was originally identified from analysis of published U. S. Geological Survey aeromagnetic mapping. Prime Meridian's close spaced airborne EM and magnetic surveys flown in 2005 confirmed the aeromagnetic anomaly and produced strong north-south conductors directly associated with strong positive magnetic features in an area of very sparse outcrop. In both the airborne and subsequent 2007 grid magnetics and HLEM ground surveys, the coincident north-south magnetic/EM anomalies were seen to be interrupted by a younger, negatively polarized east-west magnetic feature, the Late Proterozoic Deer Lake dike. Association of conductors with such dikes is a criterion for magmatically emplaced massive sulfide nickel-copper deposits in Michigan. Grid soil geochemical surveys produced anomalous base metals (Ni, Cr, Co, Cu) indicative of buried mafic rock types and/or the sought-for nickel-copper massive sulfide deposits.
Consulting geologist Doug Duskin logging 131 feet of massive sulphide (pyrrhotite and pyrite) in Bangston Lake drill core. The drill core lacked base metals however it validated Prime Meridian's exploration methodology focussed on discovering nickel-copper magmatic systems. |
In late summer 2007, a four-hole core drilling program was completed. Three of the holes were drilled from east to west, testing magnetic conductors both north and south of the dike, and one hole was drilled south-to-north to test the dike at its contact with the conductors. The magnetic conductors were explained in all cases by massive and semi-massive sulfides, pyrrhotite with lesser pyrite. The thickest intercept was 40 metres of massive sulfide (approximately 36 metres true thickness), in DDH BLS-1. There were no significant base metal or precious metal concentrations in any of the sulfide intercepts, nor in the Deer Lake dike, which proved to be a magnetite-rich diabase barren of sulfides in the hole that tested it. The sulfide-rich intercepts in the other three holes are interpreted from logging of the drill cores to be steeply dipping Archean or early Proterozoic volcanogenic massive (VMS) deposits. Although these unfortunately do not carry significant base metals, the drilling at Bangston validated the multi-disciplinary methodology that Prime Meridian is using to attempt discovery of nickel-copper massive sulfides associated with magmatic systems, which would have very similar exploration signatures.
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